Pressure-induced structural changes in the superconductor (Nd1−xSrx (Nd1–yCey) CuO4−z: A neutron diffraction study
✍ Scribed by F. Izumi; J.D. Jorgensen; P. Lightfoot; Shiyou Pei; Y. Yamada; E. Takayama-Muromachi; T. Matsumoto
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 744 KB
- Volume
- 172
- Category
- Article
- ISSN
- 0921-4534
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✦ Synopsis
The crystal structure of (Nd, s&,,J, ) (Nd,, ,,Ce,, zq )('uC)~ I (z: 0.4) was Investigated by means of TOF neutron powrdrr dltl fraction at six hydrostatic pressure up to 0.637 GPa with a He gas pressure cell. The superconducting transition temperature of this oxide has a positive pressure coefficient. dI;/dI'. of4.0 K GPax'. As the pressure is Increased. the a and c lattlcc parameters of Its tetragonal cell both decrease linearly. which leads to a similar decrease in the length of a ('u-0 ( I ) bond within a ('~0, sheet. Increasing pressure also decrease the distance between Cu and axial O(? ) atoms at a similar rate. Unfortunately. large! uncertaintics for the Cu-O(2) bond length make a quantitative comparison difficult. It is clear. however. that no pronounced changes are observed In individual Cu-0 bond lengths when compared with the overall cell compression.
We conclude that an understanding ofthc pressure effect on 7; must be rained bl considering pressure-induced changes in the overall structure rather than focussing attention on a single Cu-0 bond